


Assassination Classroom VS Saitama

by karmagisa_akabane



Category: Assassination Classroom, ワンパンマン | One-Punch Man
Genre: Class 3 E (Assassination Classroom), Gen
Language: English
Status: Completed
Published: 2019-10-12
Updated: 2019-10-14
Packaged: 2020-12-13 18:03:26
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 1,763
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21001883
Author URL: https://archiveofourown.org/users/karmagisa_akabane/pseuds/karmagisa_akabane
Summary: A betrayal from his disciple was the last thing Saitama ever expected. Not wanting to hurt Genos in their fight, Saitama only dodged, but ended up falling into a pit of darkness, letting Genos finally feel that he had defeated the invincible “One Punch Man”. However, Saitama soon landed on ground and found himself in another realm. As he meets Koro Sensei and other 3E students, he thought of them as "worthy opponents" and had the thirst of defeating each and every one of them. When Koro Sensei challenged his students to fight Saitama for practice, they did so without knowing that in one punch, he could defeat them all . As soon as Koro Sensei found out, he obviously , without a thought, went to help his students. As Koro Sensei and Saitama fights with each other, what will happen to 3E and what would they do? And what would happen to even the others in that world?





	1. Chapter 1

**Author's Note:**

> Sorry for imperfect english ><  
Feedbacks are welcomed and hope you would enjoy the story!

"COUGH, COUGH!" I was already choking up blood. As I look up with my blurry eyes, I saw one of my best disciples, Genos, looking down at me with a smirk on his face. I didn't understand - what have I done wrong as a teacher? Why did he betrayed me? For a very long time, I felt the feeling of sadness, disappointment, anger - all sorts of those feelings, rushing through my head intensely. Genos's eyes were not the same as before. It used to be so bright but now, it's so dark; it even looked evil.

Grabbing me by my neck, he hoisted me up from the slightly muddy ground. I struggled in vain. "Why..." Genos snarled softly, before yelling at me, "WHY DIDN'T YOU PUNCH ME, HUH? AM I THAT USELESS?! I'M NEVER YOUR OPPONENT; THAT'S WHAT YOU THINK, RIGHT? GAROU (the villain) WAS RIGHT. YOU NEVER SEE ME AS A STUDENT AT ALL. YOU ARE JUST TAKING ADVANTAGE OF ME!"

{No.}

"YOU ARE LOOKING DOWN ON ME, RIGHT?" He threw a punch at my face.

{No, I just-}

Suddenly, he did something I have never seen before. He dropped to the ground and commanded in some language I didn't know and before I knew it, I fell into a hole that was created by him.

{-I just don't want to hurt you.}

As the hole closes up, his mouth read, "Hope you enjoy your time in hell, sen. sei."

My eyes became heavy from all that fight, the hurtful words, his punches, everything, I want to forget them all. I guess it's not to bad to die now, after all, I had nothing left except for a useless excessive amount of power in me anyway. Everything around me was dark too so it did not matter if I were to close my eyes.

***********

"A- A- A- A- Owwie..."a voice sung in my head. I have to admit, it sound, just a tinyyyy bit, cool yet cute.

"Wow Koro Sensei, seems like your mach 20 speed is sure useful," I heard another voice. Who was Koro Sensei? I am not Koro Sensei. I started to hear chatterings from many other people as I slowly come to my consciousness. I was alive, yes but I was a little dumbfounded about that.

I could feel something bouncy and jelly under me. I poked it and heard a wail. Immediately, I jumped off. I think I had accidentally stepped on its feet and heard an even more louder cry that made me think that I had became deaf. Turning around, I was shock to see who my savior was. It didn't look like a female or male, so I came to a conclusion that it was either 3 options - 1, a robot/machine but it felt bouncy and jelly and I remembered feeling its heart beating which boils down to 2 or 3. Hence it must be either a monster or it was just my illusion. "Oh, thank you for saving me with that toy." I said to the other 28 people around me who looked more decent looking, trying to stop myself from hallucinating too much.

There was an awkward silence for a few seconds. The 28 other kids I saw broke out laughing and I think this boy called Karma insulted at the yellow monster with the creepy smiley face, "Heard that Koro Sensei? You are a toy!" That yellow monster started to shriek back at Karma and another person who I think is a girl called nagisa, stopped him as Karma shouted back at Nagisa "Shut up you little boy". It was then I found out that that "girl" was actually a boy.

In a flash, the yellow monster stood up. Were my eyes deceiving me? It stood up at like the speed of sound! Everything about it looked weird. It have many tentacles, a circular face with a big smile on it and two dot-like eyes. It looked just like an octopus at the bottom with no legs. To add on, I realized that his face could change colours. It totally was not human! Other than that it was wearing some teacher-like outfit with a tie that has a hole in it.

Sticking out its "hand" that only has 3 fingers, it said, "初めまして。私は殺先生です。よろしくお願いします。 ぬるふふふ～(Nice to meet you for the first time. I am koro sensei. Hope to work well with you. NURUFUFUFU~)" Obviously, through all these series of events, I still kept my signature face of all time, trying to stay calm.

"Ah, I am Saitama, よろしく," I replied. Scanning my surroundings, it all looked foreign to me. Am I not in Japan anymore?

To confirm my doubts, I asked, "Where am I?"

A boy with brown and golden hair came up and said, "Duh, you are on earth, stupid; it's Japan btw."

Japan? But it doesn't look like Japan at all! I guess that hole Genos created was actually a portal that sends people back to times. So when the hell was I transported to? What was going on? Many questions filled my mind but I knew that I could not ask all of them at once about everything. I have to learn about my new world I am living in, again.


	2. From today on, you will be their coach!

**Summary for the Chapter:**

> Hi! Sorry for publishing it only around today. The story summary can be found in chapter 1, but we will just state for chapter 2 as well:)
> 
> For this chapter:  
The students were first to approach Saitama, except Nagisa. Saitama then learned more about not only his environment, but also the students and teachers teaching them.   
As the day passed by, Saitama accompanied Koro Sensei and his students. He initially wanted to just sit at the side and observe the students, but Koro Sensei, as his usual self, invited Saitama to be one of 3E's coaches like Karasuma Sensei and Irina Sensei' who the students call Bitch Sensei.

"Hey baldie, are you lost?" Karma mocked at me.

I clenched my fist. The earlier incident about Genos had shaken me mentally and I couldn't control my emotions. Instantly, I shouted, "Who are you calling a baldie!"

As I was about to throw a punch across his face, I stopped for a moment, thinking about how much my punch could do to others. I turned towards Koro Sensei, who went, "NURUFUFUFU" again. I stared into in eyes. Damn, I thought. How dare he try to imitate me and keep such a horrible replica of my face! He always keeps his wide smile just like how I would always keep what others call an "idiotic expression", which I find it extremely untrue as I was born undoubtedly handsome, you know! This face of mine is the world's finest masterpiece! I asked that yellow monster, "You are a monster, aren't you?"

Koro Sensei nodded, and laughed (in his annoying way, of course.). Before he finished laughing, I charged at him. When I gave it a punch, it dodged at a speed where I couldn't see him at all. I was for the second time, surprised with his speed. He was even faster than Genos and that mindless Speed o' Sonic. Genos... I then thought of the memories - how he begged me to be his sensei, the times he were thoughtful especially in battles, willing to sacrifice himself for the people including me, and slowly, to what happened earlier. Since when have I become such an emotional man and a crybaby? I stopped and didn't dare to look up. At the corner of my eye, I saw Koro Sensei, and noticed its eyes were somewhat telling me that it understood. I felt another pain piercing through my chest. Just how much do I have to go through in a day? The guilt, sadness, frustration, it was so unbearable. 

The class was then dismissed, with only me and that Koro Sensei left at the outdoor field in front of the classroom. With his back facing me, he said, "There must've been some problems eh? It's okay to be weak for while, Saitama kun," and turned. "I know you are strong; these tentacles don't lie." 

Probably he's not that a bad monster, after all.

*************

The next day, I familiarized myself with the students AND the situation. There were 28 of them, and obviously I couldn't remember them all due to my ignorance; so I had to kept a hello kitty mini notebook given by Koro Sensei about those little students, which I absolutely wanted to throw away. As I observed the students approaching me 1 by 1 about my story, face, and somehow my hair, I noticed there was only Nagisa who didn't bother to approach me. He soon piqued my interest as he sort of reminded me of Genos. 

"Hey Nagisa, what's up?" I took the first step casually. As he looked into my eyes, it was really similar to Genos's; just younger of course. He no doubt has a good assassin's aura, but I'm afraid I'm just too strong. I might be able to kill that Koro Sensei for those kids.

"Oh, sup, it's nothing," Nagisa said blankly, watching Koro Sensei at the field, sweeping. It seems like he was 100% focused on his target to be killed. I just couldn't help but really keep thinking about Genos. No one in this assassination classroom other than Koro Sensei knew about my extreme power. Feeling like time was right, I told him, while looking at the clear blue sky, "Do you believe that, in one punch, I could defeat anyone?" It was then he listened, obviously interested. We were both, unknowingly engrossed in my story. I felt that I was chatting with Genos again, as I recited my grueling past to my now meaningless success.

Soon after, it was time for physical education lessons. Koro Sensei called for me, too. I wonder why. After he gathered everyone, he announced, "From now on, Saitama Sensei will be your coach for Physical education lessons." His face turned striped green and yellow, meaning he was confident. "If you can't beat him, it means that it's also hard to kill me for you. NURUFUFUFUFU~" I kept my normal straight face but was confused. "Huh? I never say-"

"Just him?" Terasaka asked, and came towards me, running. At around 3 feet away from me, I punched the air, which caused Terasaka to be pushed away into the forest nearby. Koro Sensei laughed again. As always, I stood there emotionless. Were they really worthy fighters? I wondered. I still want to go home and eat lunch. When I came back from my thoughts again, I saw the class, though half terrified and half amazed, were willing to compete me. This might be a good fight in the end, as I looked at Nagisa and Karma, the potential fighters mentioned. The other students might have a good deal too, which made me excited for the future. I might want to stay here for a while to train them and seek for possible worthy fighters among this interesting class.


End file.
